JP6317529B2 - Codebook and method and apparatus for generating precoder based on the codebook - Google Patents

Description

  The present disclosure relates to the field of wireless communications, and in particular to codebooks and precoders for wireless communications.

  Two-dimensional (2D) transmission has been widely studied and adopted in LTE systems. Traditional antenna arrays are arranged horizontally to form a beam in a horizontal plane. In order to take advantage of the large spatial gain of three-dimensional (3D) space, 3D multiple-input multiple-output (MIMO) channel propagation modeling has been discussed and modeled at a recent 3GPP meeting. In 3D MIMO channels, uniform panel array (UPA) antennas are employed to obtain vertical spatial gain. However, the traditional 2D codebook and channel information feedback mechanism only considers horizontal beamforming and only supports it. In order to enhance system performance by utilizing vertical spatial gain, codebooks based on 3D MIMO channels and 3D precoding matrix index feedback mechanisms are pressing issues to be addressed.

  An object of the present disclosure is to provide a method and apparatus for generating a codebook for wireless communication, a method and apparatus for generating a precoder for a 3D channel using a codebook in a base station in wireless communication, and a code in a user equipment in wireless communication A method and apparatus for facilitating precoder generation for a book is provided.

According to a first aspect of the present disclosure, a method for generating a codebook for wireless communication is provided, the codebook including a first codebook and a second codebook, the method comprising:
The first codebook (V _∀ ) has the following formula:
And determining in accordance, L represents the number of codewords in the first codebook (V _∀), M indicates the number of horizontal antenna ports, N indicates the vertical number of antenna ports, Z _l is a wireless communication Showing the l th column in any existing codebook Z for, the size of Z being N rows and L columns;
The second codebook (V _H ) is _expressed by the following formula:
, Where K is the number of codewords in the second codebook (V _H ), M is the number of horizontal antenna ports, P is the number of columns of the matrix X, and b _k is the matrix B And the matrix B is:
m = 1, ..., M / 2, k = 1, ..., K
And a step.

According to another aspect of the present disclosure, using the codebook generated by the above method, the following steps:
Selecting a first codeword (V _V ) and a second codeword (V _H ) suitable for the 3D channel from the first codebook and the second codebook, respectively, based on the channel information of the 3D channel; ,
Generating a precoder (T) for a 3D channel based on a product of a first codeword (V _V ) and a second codeword (V _H ). A method for generating a precoder for a 3D channel is provided.

According to a further aspect of the present disclosure, using the codebook generated by the above method, the following steps:
Selecting a first codeword (V _V ) and / or a second codeword (V _H ) appropriate for the channel from the first codebook and / or the second codebook, respectively, based on the channel information; When,
Transmitting precoding matrix index information to the base station, wherein the precoding matrix index information is a first precoding matrix index indicating a selected first codeword (V _V ) and / or selected. There is provided a method for facilitating precoder generation in a user equipment in wireless communication, comprising: performing a step including a second precoding matrix index indicating a second codeword (V _H ).

According to yet a further aspect of the present disclosure, an apparatus for generating a codebook for wireless communication is provided, the codebook including a first codebook and a second codebook, the apparatus comprising:
The first codebook (V _∀ ) has the following formula:
Wherein L represents the number of codewords in the first codebook (V _∀ ), M represents the number of horizontal antenna ports, N represents the number of vertical antenna ports, and Z _l represents the l columns in any existing codebook Z for wireless communication, the magnitude of Z is N rows and L columns, and modules,
The second codebook (V _H ) is _expressed by the following formula:
Wherein K is the number of codewords in the second codebook (V _H ), M is the number of horizontal antenna ports, P is the number of columns of the matrix X, b _k denotes the kth column of matrix B, where matrix B is:
m = 1, ..., M / 2, k = 1, ..., K
Which is a module.

According to still further aspects of the present disclosure, there is provided an apparatus for generating a precoder for a 3D channel at a base station in wireless communication, characterized by using a codebook generated by the above method.
Based on the channel information of the 3D channel, a first codeword (V _V ) and a second codeword (V _H ) suitable for the 3D channel are selected from the first codebook and the second codebook, respectively. Configured modules, and
And a module configured to generate a precoder (T) for the 3D channel based on a product of the first codeword (V _V ) and the second codeword (V _H ).

According to yet a further aspect of the present disclosure, there is provided an apparatus for facilitating precoder generation in a user equipment in wireless communication, characterized by using a codebook generated by the above method, the apparatus comprising:
Based on the channel information, a first codeword (V _V ) and / or a second codeword (V _H ) suitable for the channel are selected from the first codebook and / or the second codebook, respectively. A module configured with
A module configured to transmit precoding matrix index information to a base station, wherein the precoding matrix index information includes a first precoding matrix index indicative of a selected first codeword (V _V ); And a module including a second precoding matrix index indicating the selected second codeword (V _H ).

  Compared to the prior art, the codebook provided by the present disclosure is available for both horizontal and vertical beamforming, and with that codebook, the base station generates a precoder for the 3D channel. be able to. Compared to traditional precoders, the precoder provided by the present disclosure can control the azimuth and downtilt angles of the beam. Further, for the codebook, the user equipment may send a first precoding matrix index to indicate the beam downtilt angle and / or a second precoding matrix index to indicate the beam azimuth angle to the base station. it can. Compared to the prior art, the present disclosure improves system performance by utilizing the vertical spatial gain of the 3D channel.

  Other features, problems and advantages of the present disclosure will become clearer after reading the detailed description of the non-limiting embodiments with reference to the accompanying drawings. The same or similar symbols in the drawings indicate the same or similar components.

FIG. 1 shows a schematic diagram of beamforming based on a 3D channel. FIG. 2 shows a schematic diagram of a uniform panel array antenna for a 3D channel. FIG. 3 shows a flow diagram of a method for generating a codebook for wireless communication according to an embodiment of one aspect of the present disclosure. FIG. 4 shows a flow diagram of a method for generating a precoder for a 3D channel using the codebook at a base station in wireless communication according to an embodiment of another aspect of the present disclosure. FIG. 5 shows a flow diagram of a method for facilitating precoder generation for the codebook at a user equipment in wireless communication according to an embodiment of a further aspect of the present disclosure. FIG. 6 shows a schematic diagram of an apparatus for generating a codebook for wireless communication according to an embodiment of a still further aspect of the present disclosure. FIG. 7 shows a schematic diagram of an apparatus for generating a precoder for a 3D channel using the above codebook at a base station in wireless communication according to an embodiment of a still further aspect of the present disclosure. FIG. 8 shows a schematic diagram of an apparatus that facilitates precoder generation for the codebook at a user equipment in wireless communication, according to an embodiment of a still further aspect of the present disclosure.

  Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings.

  The wireless communication described here includes a communication mode using a radio signal based on GSM and 3GPP protocols, and the wireless communication network includes a communication network based on 3PP and GSM protocols. A wireless communication network typically includes a plurality of base stations each providing radio coverage to the cell in which it is located, and a plurality of user equipments (UEs) each capable of moving within or between cells. Base stations include, but are not limited to, NodeB and eNodeB. Each cell may be deployed at one base station. Each base station may comprise multiple sectors. An interface for transmitting subscriber traffic or control traffic may be utilized for intercommunication between base stations. The base station can communicate directly or indirectly with each UE. Each UE may be any electronic device that can directly or indirectly communicate with a base station wirelessly, including but not limited to a mobile phone, a PDA, and the like. Furthermore, as a preferable aspect, each base station in the wireless communication network has a plurality of antennas, and each UE also has a plurality of antennas. Furthermore, UEs can be distributed at different vertical heights. Therefore, the UE and the base station can configure a wireless communication system based on the 3D channel. Preferably, each UE and base station in the wireless communication network can transmit and receive information in a time division duplex mode (TDD mode) or a frequency division duplex mode (FDD mode). A person skilled in the art will not be limited to the above-described radio communication technology and mode in which each UE and base station transmit / receive information, and other existing or future radio communication technologies and modes in which information can be transmitted / received are also described in this document. It should be understood that if applicable to the disclosure, it should be included in the protection scope of the present disclosure and incorporated herein by reference.

  FIG. 1 shows a schematic diagram of beam forming based on a 3D channel. As shown in the drawing, the base station 1 uses the antenna array to form beams directed to the UE1 and the UE2, respectively. Since UE1 and UE2 are located at different vertical heights, the two beams directed to the UE at different vertical heights need to have different azimuth angles and different downtilt angles, ie 3D channel beamforming is It is necessary to cope with beam formation in both the horizontal direction and the vertical direction. However, existing 2D codebooks only support beam forming in the horizontal direction and cannot satisfy simultaneous beam forming in both the horizontal and vertical directions. Further, when the number of antenna ports increases, the 2D codebook designed by the structure in the prior art becomes excessive, and the overhead when the UE feeds back the precoding matrix index also becomes excessive, which impairs the system performance.

  FIG. 2 shows a schematic diagram of a uniform panel array antenna for a 3D channel. As shown, the uniform panel array antenna for the 3D channel consists of N rows and M columns of antenna elements. If each antenna element is an antenna port, the uniform panel array will have N × M antenna ports. Since the antenna elements in each column of the antenna array include N antenna elements, it can be said that there are N vertical antenna ports. Since the antenna elements in each row of the antenna array include M antenna elements, it can be said that there are M horizontal antenna ports.

  The present disclosure may be applicable to various types of antennas such as a polarization antenna and a non-polarization antenna. For simplicity of description, in the following embodiments, the base station performs signal transmission using a uniform panel array antenna having N × M antenna ports. For those skilled in the art, the uniform panel array antenna here is merely an example and is not limiting, and any antenna should be included in the protection scope of the present disclosure if applicable to the present disclosure. It should be understood that is incorporated herein by reference.

  FIG. 3 shows a flow diagram of a method for generating a codebook for wireless communication according to an embodiment of one aspect of the present disclosure, the codebook including a first codebook and a second codebook.

  Again, for clarity of description, a uniform panel array antenna having N × M antenna ports is referred to for explanation.

First, in step S31, the first codebook (V _∀ ) is determined according to the following equation.
(1)
(2)
Incidentally, L is indicated the number of codewords in the first codebook (V _∀), M represents the number of horizontal antenna ports, N is the shows the vertical number of antenna ports, Z _l is any existing for wireless communication The 1st column in the code book Z is shown, and the size of Z is N rows and L columns.

Here, β _m (1 ≦ m ≦ M) is a co-phase quantization factor for quantizing the phase difference between the columns.

The code book Z may be any code book for wireless communication in the prior art. In the following, the code book Z is shown using a DFT (Discrete Fourier Transform) matrix as an example, and the code book Z has N rows and L columns. Each column in the code book Z is shown below.
(3)
Here, l is a column index, d is an antenna interval, and λ is a wavelength of a carrier frequency. Further, θ _l is a downtilt angle, and θ _i ≠ θ _j (i ≠ j).

The size of the codeword V _V in the first codebook is [NM × M], that is, V _V is a matrix having N × M rows and M columns, M is the number of horizontal antenna ports, and N Indicates the number of vertical antenna ports.

Furthermore, the number L of codewords included in the first codebook (V _∀ ) can be adjusted according to actual system requirements.

Next, in step S32, the second codebook (V _H ) is determined according to the following equation.
(4)
(5)
(6)
K represents the number of codewords in the second codebook (V _H ), M represents the number of horizontal antenna ports, P represents the number of columns of the matrix X, and b _k represents the kth column of the matrix B. , Matrix B is as follows.
m = 1,..., M / 2, k = 1,..., K (7)

From the above, the size of the code word V _H in the second code book is [M × 2P], that is, V _H is a matrix of M rows and 2P columns, and M indicates the number of horizontal antenna ports. I understand.

Furthermore, the number K of codewords contained in the second codebook (V _H ) can be adjusted according to actual system requirements.

In a preferred embodiment, the codebook for wireless communication includes a third codebook (V _S ) in addition to the first codebook and the second codebook.

In step S33 (not shown), a third codebook (V _S ) is determined according to the following equation.
(8)
(9)
Q indicates the number of codewords in the third codebook (V _S ), P is the number of columns of the matrix X used in the second codebook, r indicates the number of streams,
Denotes a vector having t elements, the s-th element is 1 and the remaining elements are 0.

From the above, the size of the code word V _S in the third code book is [2P × r], that is, Vs is a matrix having 2P rows and r columns, and P is used in the second code book. It can be seen that r indicates the number of streams, and r indicates the number of streams.

  FIG. 4 shows a flow diagram of a method for generating a precoder for a 3D channel using the codebook in a base station in wireless communication according to an embodiment of another aspect of the present disclosure.

In step S41, the base station, based on the channel information of the 3D channel, respectively, the first codeword (V _V ) and the second codeword (V _V ) suitable for the 3D channel from the first codebook and the second codebook ( _VH ) is selected.

Here, the channel information may be acquired in various acquisition modes. For example, in a TDD network, the base station uses the correlation between the uplink channel and the downlink channel to convert the uplink channel information from the UE to the base station as the downlink channel information from the base station to the UE. , Can be estimated by obtaining a sounding signal transmitted by the UE, and the channel information is preferably a channel matrix. For 3D channels, the channel information may include vertical plane channel information and horizontal plane channel information. For another example, in an FDD network, the UE can estimate the channel matrix and select a codeword suitable for the channel from the codebook using the estimated channel matrix according to a predetermined selection criterion, eg, a maximum throughput criterion. The index value (precoding matrix index: PMI) in the codebook is reported to the base station so that the base station can use the acquired PMI as channel information. Further, when the wireless communication system uses the codebook proposed by the present disclosure, the base station can receive precoding matrix index information from the UE, and the precoding matrix index information is selected from the selected first codeword ( A first precoding matrix index (vPMI) indicating V _V ) and / or a second precoding matrix index (hPMI) indicating the selected second codeword (V _H ). Further, in a preferred embodiment, the precoding matrix index information received by the base station from the UE is a third precoding matrix index (sPMI) indicating a selected third codeword (V _S ) from the UE. Including.

  In one embodiment, the base station receives each precoding matrix index from the UE in the same subframe, and the precoding matrix index includes one or more of the vPMI, hPMI and sPMI. Further, the frequency of receiving the precoding matrix index by the base station can be adjusted according to actual system requirements.

  In another embodiment, the base station receives each precoding matrix index from the UE in a plurality of subframes, and the precoding matrix index includes one or more of the vPMI, hPMI, and sPMI. Further, in each subframe of the plurality of subframes, the base station may receive one or more precoding matrix indexes. For example, the base station may receive vPMI in the nth subframe and receive hPMI and sPMI in the mth subframe. For another example, the base station may receive vPMI, hPMI, and sPMI, respectively, in three different subframes. Furthermore, the frequency with which each precoding matrix index is received by the base station may be the same or different. For example, hPMI may be received by the base station more frequently than vPMI. For another example, the sPMI is vPMI because the third codeword is used to reflect short-term channel information, while the first and second codewords are used to reflect long-term channel information. And may be received by the base station more frequently than hPMI. Also, the reception frequency of each precoding matrix index can be adjusted according to actual system requirements.

  It should be understood by those skilled in the art that the description regarding channel information and the manner in which the channel information is obtained are merely illustrative and not limiting. Various other embodiments exist without departing from the spirit or scope of the present disclosure and are incorporated herein by reference.

Next, based on the channel information of the 3D channel, the base station respectively receives a first codeword (V _V ) and a second codeword suitable for the 3D channel from the first codebook and the second codebook ( _VH ) is selected.

In some embodiments, if the 3D channel information is, for example, a channel matrix, the base station may use a first codeword suitable for the 3D channel (V _V based on vertical plane channel information included in the channel matrix, eg, according to a maximum throughput criterion. ) And the first codeword is referred to as a vertical precoding matrix for controlling the downtilt angle of the formed beam. Further, the base station can determine whether the second codeword can indicate the azimuth angle of the formed beam, for example, based on the horizontal plane channel information included in the 3D channel information according to the maximum throughput criterion, from the second codebook. A second codeword (V _H ) suitable for the above is selected. Thus, a pair of beams having azimuth angle indicated by the downtilt angle and V _H indicated by V _V is, first code word selected (V _V) and a second codeword (V _H) It will be formed based on.

In other embodiments, the channel information is precoding matrix index information reported by the UE, and the wireless communication system uses a codebook provided by the present disclosure. Accordingly, as described above, the precoding matrix index information obtained by the base station includes the first precoding matrix index (vPMI) indicating the first codeword (V _V ) selected by the UE and / or the UE. A second precoding matrix index (hPMI) indicating the second codeword (V _H ) selected by. The base station obtains corresponding codewords from the first codebook and the second codebook based on vPMI and hPMI respectively, the first codeword (V _V ) and the second codeword ( V _H ). The first codeword (V _V ) will indicate the downtilt angle of the formed beam, and the second codeword (V _H ) will indicate the azimuth angle of the formed beam. Thus, a pair of beams having azimuth angle indicated by the downtilt angle and V _H indicated by V _V is, first code word selected (V _V) and a second codeword (V _H) It will be formed based on.

  Furthermore, in other embodiments, the base station may 3D from the first codebook and the second codebook, respectively, along with the estimated channel matrix and precoding matrix index information reported by the UE. A first codeword and a second codeword suitable for the channel may be selected. For example, if the precoding matrix index information reported by the UE includes only hPMI, the base station selects the second codeword from the second codebook based on the hPMI according to the above-described method, and the estimated channel matrix Based on the first codebook, a first codeword is selected. Further, if the precoding matrix index information reported by the UE includes vPMI and hPMI, the base station responds from the first codebook and the second codebook based on the channel matrix with reference to the vPMI and hPMI. Codewords can be selected.

Next, in step S42, the base station generates a precoder (T) for the 3D channel based on the product of the first codeword (V _V ) and the second codeword (V _H ). Specifically, the base station first multiplies the _{V H} to _{V V.} As described above, the size of the first code word (V _V ) is [NM × M], the size of the second code word (V _H ) is [M × 2P], and N is vertical Indicates the number of antenna ports, M indicates the number of horizontal antenna ports, and P indicates the number of columns of the matrix X used by the second codebook. Thus, the product of _{V V} and _{V H} are _V V _{V H} magnitude is [NM × 2P], i.e., a matrix having N × M rows and 2P columns. After that, the base station selects r columns from V _V V _H as a precoder (T). R indicates the number of streams. In one embodiment, the base station may select the r sequence as a precoder (T) from the 2P sequence, eg, according to a maximum throughput criterion. In other embodiments, selected base station, the V _V V _H, by multiplying a predetermined fixed codeword is a matrix having a 2P rows and r columns, the r columns in V _V V _H as precoder (T) can do. Since the first codeword (V _V ) will indicate the downtilt angle of the formed beam and the second codeword (V _H ) will indicate the azimuth angle of the formed beam, V _V A set of beams having a downtilt angle indicated by and an azimuth angle indicated by _VH will be formed based on the generated precoder (T).

In a preferred embodiment, the base station has the first codeword (V _V ) and the second codeword (V _H ) selected according to the above method, and then sets the channel information and the number of streams corresponding to the channel. Based on this, a third codeword (V _S ) suitable for the 3D channel can be further selected from the third codebook. Then, the base station generates a precoder (T) for the 3D channel based on the product of V _V , V _H and V _S. In an embodiment, if the channel information is a channel matrix, the base station may select a third code suitable for a 3D channel from a third codebook based on, for example, a channel matrix and the number of streams corresponding to the channel according to a maximum throughput criterion. Select the word (V _S ). As described above, the magnitude of V _S is [2P × r], P is the number of columns of the matrix X used by the second codebook, and r is the number of streams. In another embodiment, if the precoding matrix index information reported by the UE includes a third precoding matrix index (sPMI) indicating a third codeword (V _S ) selected by the UE, the base station Selects the corresponding codeword as the third codeword V _S suitable for the 3D channel from the third codebook according to sPMI.

Next, the base station generates a precoder (T) for the 3D channel based on the product of V _V , V _H and V _S. Specifically, the base station multiplies the _{V H} to _{V V} First, as described above, to obtain a _V V _{V H} of the magnitude of [NM × 2P]. Then, the base station multiplies the _{V S} to _V V _{V H,} the value of _{V S} is [2P × r], to obtain a _{V V V} H _{V S} of the magnitude of [NM × r]. R indicates the number of streams. The base station uses V _V V _H V _S as a precoder (T), which is a matrix having N × M rows and r columns. Since the first codeword (V _V ) will indicate the downtilt angle of the formed beam and the second codeword (V _H ) will indicate the azimuth angle of the formed beam, V _V A set of beams having a downtilt angle indicated by and an azimuth angle indicated by _VH will be formed based on the generated precoder (T).

In other embodiments, the base station may generate a precoder for the 2D channel using the codebook provided by this disclosure. In particular, the base station can select a second codeword V _H of size [M × 2P] from the second codebook according to the above aspect based on horizontal plane channel information or hPMI, and then for example The r sequence is used as a precoder (T) for the 2D channel according to the maximum throughput criterion. In another example, the base station selects the second codeword V _H from the second codebook based on the horizontal plane channel information or hPMI, and [2P × r] from the third codeword according to the above aspect. can select a third codeword _{V S} size, then, get multiplied by _{V S} to _{V H} the size of the _V H _{V S} of [M × r] as precoder (T) for the 2D channel To do. It can be seen that the codebook provided by the present disclosure can be applied to conventional 2D channels in addition to 3D channels.

  FIG. 5 shows a flow diagram of a method for facilitating precoder generation using the codebook at a UE in wireless communication according to an embodiment of a further aspect of the present disclosure.

In step S51, the UE, based on the channel information, from the first codebook and / or the second codebook, respectively, the first codeword (V _V ) and / or the second codeword ( _VH ) is selected. Specifically, the UE can perform channel estimation according to the received reference signal to derive a channel matrix, and then a code suitable for the channel from the codebook based on the channel matrix according to a predetermined selection criterion. Select a word.

In one embodiment, the UE is configured with a reference signal for the vertical antenna port, and then the UE can estimate a vertical plane channel matrix based on this reference signal, eg, from a first codebook according to a maximum throughput criterion. Select a first codeword (V _V ) appropriate for the channel. The first codeword (V _V ) may be used to indicate the downtilt angle of the beam that is aimed at the UE.

In other embodiments, the UE is configured with a reference signal for the horizontal antenna port, after which the UE estimates a horizontal plane channel matrix based on this reference signal, eg suitable for the channel from the second codebook according to the maximum throughput principle The second code word (V _H ) is selected. The second codeword (V _H ) can be used to indicate the azimuth angle of the beam directed at the UE.

In a further embodiment, the UE is configured with two sets of reference signals for the vertical antenna port and the horizontal antenna port, respectively, after which the UE estimates a vertical plane channel matrix and a horizontal plane channel matrix based on the two sets of reference signals, respectively. Then, for example, according to a maximum throughput criterion, selecting a first codeword (V _V ) suitable for the channel from the first codebook and a second codeword (V _H ) suitable for the channel from the second codebook. it can. Further, the first codeword (V _V ) may indicate the downtilt angle of the beam directed toward the UE, and the second codeword (V _H ) may indicate the azimuth angle of the beam directed toward the UE.

In a preferred embodiment, the UE may further select a third codeword (V _S ) appropriate for the channel from the third codebook based on the channel information corresponding to the channel and the number of streams. For example, the UE acquires a vertical plane channel matrix and / or a horizontal plane channel matrix based on a reference signal for a vertical antenna port and / or a horizontal antenna port. Then, the UE selects a third codeword (V _S ) suitable for the channel from the third codebook based on, for example, the channel matrix corresponding to the channel and the number of streams according to the maximum throughput criterion.

Thereafter, in step S52, the UE obtains the first precoding matrix index information (vPMI) indicating the selected first codeword (V _V ) and / or the selected second codeword (V _H ). Precoding matrix index information including second precoding matrix index information (hPMI) shown is transmitted to the base station. Further, in a preferred embodiment, the precoding matrix index information transmitted by the UE to the base station includes third precoding matrix index information (sPMI) indicating the selected third codeword (V _S ). In addition.

  In one embodiment, the UE transmits each precoding matrix index information indicating each selected codeword to the base station in the same subframe. In particular, each precoding matrix index information includes one or more of vPMI, hPMI, and sPMI, and the frequency of transmitting the precoding matrix index by the UE may be adjusted according to actual system requirements.

  In other embodiments, the UE transmits each precoding matrix index information of each selected codeword to the base station in multiple subframes. In particular, each precoding matrix index information may include one or more of the above vPMI, hPMI, and sPMI. Further, in each subframe of the plurality of subframes, the UE may transmit one or more precoding matrix index information. For example, the UE may transmit vPMI in the nth subframe and transmit hPMI and sPMI in the mth subframe. For another example, the UE may transmit vPMI, hPMI, and sPMI, respectively, in three different subframes. Further, in a preferred embodiment, the UE may transmit each precoding matrix index with the same frequency or with a different frequency. For example, hPMI may be transmitted by the UE more frequently. For another example, sPMI is vPMI because the third codeword is for reflecting short-term channel information, while the first and second codewords are for reflecting long-term channel information. And may be transmitted by the UE more frequently than hPMI. The transmission frequency of each precoding matrix index may be adjusted according to actual system requirements.

  FIG. 6 shows a schematic diagram of an apparatus for generating a codebook for wireless communication according to an embodiment of a still further aspect of the present disclosure, wherein the codebook includes a first codebook and a second codebook. Including.

  Again, for simplicity of description, a uniform panel array antenna having N × M antenna ports is referenced for illustration.

First, a module 61 configured to determine a first codebook (hereinafter referred to as a first codebook determination module 61) determines a first codebook (V _∀ ) according to the following equation.
(1)
(2)
Incidentally, L is indicated the number of codewords in the first codebook (V _∀), M represents the number of horizontal antenna ports, N is the shows the vertical number of antenna ports, Z _l is any existing for wireless communication The 1st column in the code book Z is shown, and the size of Z is N rows and L columns.

Here, β _m (1 ≦ m ≦ M) is a co-phase quantization factor for quantizing the phase difference between the columns.

The code book Z may be any code book for wireless communication in the prior art. In the following, the code book Z is shown using a DFT (Discrete Fourier Transform) matrix as an example, and the code book Z has N rows and L columns. Each column in the code book Z is shown below.
(3)
Here, l is a column index, d is an antenna interval, and λ is a wavelength of a carrier frequency. Further, θ _l is a downtilt angle, and θ _i ≠ θ _j (i ≠ j).

The size of the codeword V _V in the first codebook is [NM × M], that is, V _V is a matrix having N × M rows and M columns, M is the number of horizontal antenna ports, and N Indicates the number of vertical antenna ports.

Furthermore, the number L of codewords included in the first codebook (V _∀ ) can be adjusted according to actual system requirements.

Next, a module 62 configured to determine the second codebook (hereinafter referred to as the second codebook determination module 62) determines the second codebook (V _H ) according to the following equation:
(4)
(5)
(6)
K represents the number of codewords in the second codebook (V _H ), M represents the number of horizontal antenna ports, P represents the number of columns of the matrix X, and b _k represents the kth column of the matrix B. , Matrix B is as follows.
m = 1,..., M / 2, k = 1,..., K (7)

From the above, the size of the code word V _H in the second code book is [M × 2P], that is, V _H is a matrix having M rows and 2P columns, and M indicates the number of horizontal antenna ports. I understand.

Furthermore, the number K of codewords contained in the second codebook (V _H ) can be adjusted according to actual system requirements.

In a preferred embodiment, the codebook for wireless communication includes a third codebook (V _S ) in addition to the first codebook and the second codebook.

A module 63 (not shown) configured to determine a third codebook determines a third codebook (V _S ) according to the following equation:
(8)
(9)
Q indicates the number of codewords in the third codebook (V _S ), P is the number of columns of the matrix X used in the second codebook, r indicates the number of streams,
Denotes a vector having t elements, the s-th element is 1 and the remaining elements are 0.

From the above, the size of the code word V _S in the third code book is [2P × r], that is, Vs is a matrix having 2P rows and r columns, and P is used in the second code book. It can be seen that r indicates the number of streams, and r indicates the number of streams.

  FIG. 7 shows a schematic diagram of an apparatus for generating a precoder for a 3D channel using the above codebook in a base station in wireless communication according to an embodiment of a still further aspect of the present disclosure.

Based on the channel information of the 3D channel, a first codeword (V _V ) and a second codeword (V _H ) suitable for the 3D channel are selected from the first codebook and the second codebook, respectively. The configured module 71 (hereinafter referred to as the first and second codeword selection module 71) is adapted to the 3D channel from the first codebook and the second codebook based on the channel information of the 3D channel, respectively. One code word (V _V ) and a second code word (V _H ) are selected.

Here, the first and second codeword selection modules 71 may acquire channel information in various acquisition modes. For example, in a TDD network, the first and second codeword selection module 71 uses the correlation between the uplink channel and the downlink channel to obtain uplink channel information from the UE to the base station. Can be estimated by obtaining a sounding signal transmitted by the UE as downlink channel information from the UE to the UE, and the channel information is preferably a channel matrix. For 3D channels, the channel information may include vertical plane channel information and horizontal plane channel information. For another example, in an FDD network, the UE can estimate the channel matrix and select a codeword suitable for the channel from the codebook using the estimated channel matrix according to a predetermined selection criterion, eg, a maximum throughput criterion. The codeword index value (precoding matrix index: PMI) in the codebook is reported to the base station so that the first and second codeword selection modules 71 can use the acquired PMI as channel information. . Further, when the wireless communication system uses the code book proposed by the present disclosure, a module 73 (not shown) configured to receive precoding matrix index information from the UE (hereinafter, precoding matrix index information receiving module 73). The first precoding matrix index (vPMI) indicating the selected first codeword (V _V ) and / or the second precoding indicating the selected second codeword (V _H ). Precoding matrix index information including a matrix index (hPMI) may be received from the UE. Further, in a preferred embodiment, the precoding matrix index information received by the precoding matrix index information receiving module 73 from the UE is a third pre-code indicating the selected third codeword (V _S ) from the UE. Also includes a coding matrix index (sPMI).

  In an embodiment, the precoding matrix index information receiving module 73 receives each precoding matrix index from the UE in the same subframe, and the precoding matrix index includes one or more of the vPMI, hPMI, and sPMI. Further, the frequency of receiving the precoding matrix index by the base station can be adjusted according to actual system requirements.

  In another embodiment, the precoding matrix index information receiving module 73 receives each precoding matrix index from the UE in a plurality of subframes, and the precoding matrix index includes one or more of the vPMI, hPMI, and sPMI. Further, in each subframe of the plurality of subframes, the base station may receive one or more precoding matrix indexes. For example, the precoding matrix index information receiving module 73 may receive vPMI in the nth subframe and receive hPMI and sPMI in the mth subframe. For another example, the precoding matrix index information receiving module 73 may receive vPMI, hPMI, and sPMI, respectively, in three different subframes. Furthermore, the frequency with which each precoding matrix index is received by the precoding matrix index information receiving module 73 may be the same or different. For example, hPMI may be received by the base station more frequently than vPMI. For another example, the sPMI is vPMI because the third codeword is used to reflect short-term channel information, while the first and second codewords are used to reflect long-term channel information. And the precoding matrix index information receiving module 73 may be received at a frequency higher than that of hPMI. Also, the reception frequency of each precoding matrix index can be adjusted according to actual system requirements.

  It should be understood by those skilled in the art that the description regarding channel information and the manner in which the channel information is obtained are merely illustrative and not limiting. Various other embodiments exist without departing from the spirit or scope of the present disclosure and are incorporated herein by reference.

Next, based on the channel information of the 3D channel, the first and second codeword selection modules 71 respectively select the first codeword (V) suitable for the 3D channel from the first codebook and the second codebook, respectively. _V ) and the second codeword ( _VH ) are selected.

In some embodiments, if the 3D channel information is a channel matrix, for example, the first and second codeword selection modules 71 are suitable for the 3D channel based on vertical plane channel information included in the channel matrix, for example according to a maximum throughput criterion. The first codeword (V _V ) is selected, and the first codeword is referred to as a vertical precoding matrix for controlling the downtilt angle of the formed beam. Furthermore, the first and second codeword selection module 71 is based on horizontal plane channel information included in the 3D channel information, eg according to the maximum throughput criterion, so that the second codeword can indicate the azimuth angle of the formed beam. The second code word (V _H ) suitable for the 3D channel is selected from the second code book. Thus, a pair of beams having azimuth angle indicated by the downtilt angle and V _H indicated by V _V is, first code word selected (V _V) and a second codeword (V _H) It will be formed based on.

In other embodiments, the channel information is precoding matrix index information reported by the UE, and the wireless communication system uses a codebook provided by the present disclosure. Therefore, as described above, the precoding matrix index information obtained by the precoding matrix index information receiving module 73 is the first precoding matrix index (V _V ) indicating the first codeword (V _V ) selected by the UE. vPMI) and / or a second precoding matrix index (hPMI) indicating a second codeword (V _H ) selected by the UE. The first and second codeword selection modules 71 convert the corresponding codewords from the first codebook and the second codebook to the first codeword (V) suitable for the 3D channel based on vPMI and hPMI, respectively. _V ) and the second code word (V _H ). The first codeword (V _V ) will indicate the downtilt angle of the formed beam, and the second codeword (V _H ) will indicate the azimuth angle of the formed beam. Thus, a pair of beams having azimuth angle indicated by the downtilt angle and V _H indicated by V _V is, first code word selected (V _V) and a second codeword (V _H) It will be formed based on.

  Further, in other embodiments, the first and second codeword selection modules 71 may combine the corresponding codewords with the first codecode together with the estimated channel matrix and precoding matrix index information reported by the UE, respectively. A first codeword and a second codeword suitable for the 3D channel may be selected from the book and the second codebook. For example, if the precoding matrix index information reported by the UE includes only hPMI, the first and second codeword selection modules 71 may receive the second code from the second codebook based on the hPMI according to the method described above. A word is selected and a first codeword is selected from the first codebook based on the estimated channel matrix. Further, if the precoding matrix index information reported by the UE includes vPMI and hPMI, the first and second codeword selection modules 71 refer to the vPMI and hPMI and use the first code based on the channel matrix. A corresponding codeword may be selected from the book and the second codebook.

Next, a module 72 (hereinafter, precoder generation module) configured to generate a precoder (T) for the 3D channel based on the product of the first codeword (V _V ) and the second codeword (V _H ). 72) generates a precoder (T) for the 3D channel based on the product of the first codeword (V _V ) and the second codeword (V _H ). Specifically, precoder generation module 72 is first multiplied by the _{V H} to _{V V.} As described above, the size of the first code word (V _V ) is [NM × M], the size of the second code word (V _H ) is [M × 2P], and N is vertical Indicates the number of antenna ports, M indicates the number of horizontal antenna ports, and P indicates the number of columns of the matrix X used by the second codebook. Thus, the product of _{V V} and _{V H} are _V V _{V H} magnitude is [NM × 2P], i.e., a matrix having N × M rows and 2P columns. Thereafter, the precoder generation module 72 selects r columns from V _V V _H as the precoder (T). R indicates the number of streams. In one embodiment, the precoder generation module 72 may select the r column as a precoder (T) from the 2P sequence, eg, according to a maximum throughput criterion. In other embodiments, precoder generation module _72, the V V _{V H,} by multiplying a predetermined fixed codeword is a matrix having a 2P rows and r columns, r columns in _V V _{V H} as precoder (T) Can be selected. Since the first codeword (V _V ) will indicate the downtilt angle of the formed beam and the second codeword (V _H ) will indicate the azimuth angle of the formed beam, V _V A set of beams having a downtilt angle indicated by and an azimuth angle indicated by _VH will be formed based on the generated precoder (T).

In a preferred embodiment, the first and second codeword selection module 71 has a first codeword (V _V ) and a second codeword (V _H ) selected according to the above method, and then the channel A module 74 (not shown) configured to select a third codeword (V _S ) suitable for the 3D channel from a third codebook based on channel information and the number of streams corresponding to A third codeword (V _S ) suitable for the 3D channel from the third codebook based on the channel information corresponding to the channel and the number of streams. Then, the precoder generation module 72 generates a precoder (T) for the 3D channel based on the product of V _V , V _H and V _S. In some embodiments, if the channel information is a channel matrix, the third codeword selection module 74 may switch from a third codebook to a 3D channel based on the channel matrix and the number of streams corresponding to the channel, eg, according to a maximum throughput criterion. Select a suitable third codeword (V _S ). As described above, the magnitude of V _S is [2P × r], P is the number of columns of the matrix X used by the second codebook, and r is the number of streams. In another embodiment, if the precoding matrix index information reported by the UE includes a third precoding matrix index (sPMI) indicating a third codeword (V _S ) selected by the UE, the base station Selects the corresponding codeword as the third codeword V _S suitable for the 3D channel from the third codebook according to sPMI.

Next, the precoder generation module 72 generates a precoder (T) for the 3D channel based on the product of V _V , V _H and V _S. Specifically, precoder generation module 72 is first multiplied by the _{V H} to _{V V,} as described above, to obtain a _V V _{V H} of the magnitude of [NM × 2P]. Then, multiplied by _{V S} to precoder generation module 72 _V V _{V H,} the value of _{V S} is [2P × r], to obtain a _{V V V} H _{V S} of the magnitude of [NM × r]. R indicates the number of streams. Precoder generation module 72 uses V _{V VH} V _S as a precoder (T), which is a matrix having N × M rows and r columns. Since the first codeword (V _V ) will indicate the downtilt angle of the formed beam and the second codeword (V _H ) will indicate the azimuth angle of the formed beam, V _V A set of beams having a downtilt angle indicated by and an azimuth angle indicated by _VH will be formed based on the generated precoder (T).

In other embodiments, the precoder generation module 72 can generate a precoder for a 2D channel using a codebook provided by the present disclosure. In particular, the precoder generation module 72 can select a second codeword V _H of size [M × 2P] from the second codebook according to the above aspect based on horizontal plane channel information or hPMI, and then For example, the r sequence is used as a precoder (T) for a 2D channel according to a maximum throughput criterion. In another example, the third code with the first and second codeword selection module 71 selects a second codeword V _H from the second codebook according to the aforementioned embodiments on the basis of the horizontal channel information or hPMI The word selection module 74 selects a third code word V _S having a size of [2P × r] from the third code word, and then the precoder generation module 74 multiplies V _H by V _S to obtain [M × r obtained as precoder (T) with respect to the magnitude of _V H _{V S} the 2D channel. It can be seen that the codebook provided by the present disclosure can be applied to conventional 2D channels in addition to 3D channels.

  FIG. 8 shows a schematic diagram of an apparatus for facilitating precoder generation using the above codebook in a UE in wireless communication, according to an embodiment of a still further aspect of the present disclosure.

A first codeword (V _V ) and / or a second codeword (V _H ) suitable for the channel are selected from the first codebook and / or the second codebook, respectively, based on the channel information. The configured UE module 81 (hereinafter referred to as UE first and second codeword selection module 81) is suitable for the channel from the first codebook and / or the second codebook, respectively, based on the channel information. The first code word (V _V ) and / or the second code word (V _H ) are selected. Specifically, the first and second codeword selection module 81 can perform channel estimation according to the received reference signal so as to derive a channel matrix, and then based on the channel matrix according to a predetermined selection criterion. Select the codeword appropriate for the channel from the codebook.

In one embodiment, the UE is configured with a reference signal for the vertical antenna port, and then the UE can estimate a vertical plane channel matrix based on this reference signal, eg, from a first codebook according to a maximum throughput criterion. Select a first codeword (V _V ) appropriate for the channel. The first codeword (V _V ) may be used to indicate the downtilt angle of the beam that is aimed at the UE.

In another embodiment, the UE is configured with a reference signal for the horizontal antenna port, after which the first and second codeword selection module 81 estimates a horizontal plane channel matrix based on this reference signal, eg, maximum throughput principle To select a second codeword (V _H ) suitable for the channel from the second codebook. The second codeword (V _H ) can be used to indicate the azimuth angle of the beam directed at the UE.

In a further embodiment, the UE is configured with two sets of reference signals for the vertical antenna port and the horizontal antenna port, respectively, after which the first and second codeword selection modules 81 are each based on the two sets of reference signals based on the vertical plane. Estimate the channel matrix and the horizontal plane channel matrix, then a first codeword (V _V ) suitable for the channel from the first codebook and a second code suitable for the channel from the second codebook, eg according to the maximum throughput criterion The word (V _H ) can be selected. Further, the first codeword (V _V ) may indicate the downtilt angle of the beam directed toward the UE, and the second codeword (V _H ) may indicate the azimuth angle of the beam directed toward the UE.

In a preferred embodiment, a module at the UE configured to select a third codeword (V _S ) appropriate for the channel from a third codebook based on channel information corresponding to the channel and the number of streams. 83 (not shown) (hereinafter referred to as the UE third codeword selection module 83), the third codeword (V) suitable for the channel from the third codebook based on the channel information corresponding to the channel and the number of streams. _S ) can be further selected. For example, the UE third codeword selection module 83 obtains a vertical plane channel matrix and / or a horizontal plane channel matrix based on a reference signal for a vertical antenna port and / or a horizontal antenna port. Then, the UE third codeword selection module 83 obtains a third codeword (V _S ) suitable for the channel from the third codebook based on, for example, the channel matrix corresponding to the channel and the number of streams according to the maximum throughput criterion. select.

Thereafter, a first precoding matrix index (vPMI) indicating the selected first codeword (V _V ) and / or a second precoding matrix index indicating the selected second codeword (V _H ). The module 82 configured to transmit the precoding matrix index information including (hPMI) to the base station (hereinafter referred to as the precoding matrix index information transmission module 82) is the first codeword (V _V ) selected. Base precoding matrix index information including first precoding matrix index information (vPMI) indicating the second precoding matrix index information (hPMI) indicating the selected second codeword (V _H ) Send to the station. Further, in a preferred embodiment, the precoding matrix index information transmitted to the base station by the precoding matrix index information transmission module 82 is a third precoding indicating a selected third codeword (V _S ). Further included is matrix index information (sPMI).

  In one embodiment, the precoding matrix index information transmission module 82 transmits each precoding matrix index information indicating each selected codeword to the base station in the same subframe. In particular, each precoding matrix index information includes one or more of vPMI, hPMI and sPMI, and the frequency of transmitting the precoding matrix index by the precoding matrix index information transmission module 82 is adjusted according to actual system requirements. Can be done.

  In other embodiments, the precoding matrix index information transmission module 82 transmits each precoding matrix index information of each selected codeword to the base station in multiple subframes. In particular, each precoding matrix index information may include one or more of the above vPMI, hPMI, and sPMI. Further, in each subframe of the plurality of subframes, the precoding matrix index information transmission module 82 may transmit one or more precoding matrix index information. For example, the precoding matrix index information transmission module 82 may transmit vPMI in the nth subframe and transmit hPMI and sPMI in the mth subframe. For another example, the precoding matrix index information transmission module 82 may transmit vPMI, hPMI, and sPMI, respectively, in three different subframes. Further, in a preferred embodiment, the precoding matrix index information transmission module 82 may transmit each precoding matrix index with the same frequency or with a different frequency. For example, hPMI may be transmitted by the UE more frequently. For another example, sPMI is vPMI because the third codeword is for reflecting short-term channel information, while the first and second codewords are for reflecting long-term channel information. And may be transmitted by the UE more frequently than hPMI. The transmission frequency of each precoding matrix index may be adjusted according to actual system requirements.

  Note that the present disclosure may be implemented in software and / or a combination of software and hardware. For example, each module of the present disclosure may be implemented by an application specific integrated circuit (ASIC) or any other similar hardware device. In one embodiment, the software program of the present disclosure may be executed by a processor to perform the steps or functions described above. Similarly, the software programs of the present disclosure (including associated data structures) may also be stored on a computer readable recording medium, such as RAM memory, magnetic or optical drivers, or soft floppies or similar devices. Further, some steps or functions of the present disclosure may be implemented by circuitry that cooperates with hardware, eg, a processor, to perform various steps or functions.

  Also part of the present disclosure is a computer program product, for example a computer program instruction that, when executed by a computer, can invoke or provide the method and / or technical solution according to the present disclosure via the operation of the computer Can be applied as Also, the computer instructions that invoke the method of the present disclosure are stored in a fixed or movable recording medium, transmitted via broadcast or data flow in other signal carrying media, and / or operated based on the program instructions Can be stored in a working memory. Here, in an embodiment according to the present disclosure, an apparatus comprises a memory for storing computer program instructions and a processor for executing the program instructions, when the computer program instructions are executed by the processor, the apparatus is disclosed in the present disclosure. Triggered to run a method and / or technical solution according to embodiments.

  It will be apparent to those skilled in the art that the present disclosure is not limited to the details of the exemplary embodiments described above, and that the present disclosure can be implemented in other embodiments without departing from the spirit and basic structure of the disclosure. . Accordingly, in any aspect, the embodiments are to be regarded as illustrative and not restrictive, and the scope of the present disclosure is limited not by the above description, but by the appended claims. Accordingly, all modifications that are intended to fall within the meaning and range of equivalent elements of the claims are to be embraced within this disclosure. Any reference signs in the claims should not be construed as limiting the claim. Further, the term “comprising” does not exclude other parts or steps, and it is obvious that the singular does not exclude the plural. Multiple parts or modules recited in the system claims may be implemented by a single part or module via software or hardware. Terms such as first and second are used to indicate names and do not indicate any particular order.

Claims (15)

A method of generating a codebook for wireless communication, wherein the codebook includes a first codebook and a second codebook, the method comprising:
The first codebook (V _∀ ) has the following formula:
And determining in accordance, L represents the number of codewords in the first codebook (V _∀), M indicates the number of horizontal antenna ports, N indicates the vertical number of antenna ports, Z _l is a radio communication Showing the l-th column in any existing codebook Z for, the size of Z being N rows and L columns;
The second codebook (V _H ) is _expressed by the following formula:
K represents the number of codewords in the second codebook (V _H ), M represents the number of horizontal antenna ports, P represents the number of columns of the matrix X, and b _k represents the matrix Show the kth column of B, and the matrix B is:
m = 1, ..., M / 2, k = 1, ..., K
A method comprising the steps of: The codebook for wireless communication further includes a third codebook (V _S ), the method comprising:
A third codebook (V _S ) can be expressed as:
Further comprising the step of determining according to
Q indicates the number of codewords in the third codebook (V _S ), P is the number of columns of the matrix X used in the second codebook, r indicates the number of streams,
The method of claim 1, wherein denotes a vector having t elements, the s th element is 1, and the remaining elements are 0. A method for generating a precoder for a 3D channel in a base station in wireless communication, characterized in that the following steps are performed using a codebook generated by the method according to claim 1 or 2;
Based on the channel information of the 3D channel, a first codeword (V _V ) and a second codeword (V _H ) suitable for the 3D channel are selected from the first codebook and the second codebook, respectively. Steps,
Generating a precoder (T) for the 3D channel based on a product of the first codeword (V _V ) and the second codeword (V _H ). Selecting a third codeword (V _S ) suitable for the 3D channel from a third codebook based on the channel information corresponding to the channel and the number of streams;
Generating the precoder (T) for the 3D channel based on a product of the first codeword (V _V ) and the second codeword (V _H );
Generating a precoder (T) for the 3D channel based on a product of the first codeword (V _V ), the second codeword (V _H ), and the third codeword (V _S ); The method of claim 3 comprising. The channel information includes precoding matrix index information transmitted by a user equipment, the method comprising:
Receiving precoding matrix index information from the user equipment, wherein the precoding matrix index information includes a first precoding matrix index indicating a selected first codeword (V _V ) and a selected The method according to claim 3 or 4, further comprising the step of including a second precoding matrix index indicating the second codeword (V _H ). A method for facilitating precoder generation in a user equipment in wireless communication, characterized in that the following steps are performed using a codebook generated by the method according to claim 1 or 2;
Based on the channel information, a first codeword (V _V ) and / or a second codeword (V _H ) suitable for the channel are selected from the first codebook and / or the second codebook, respectively. Steps,
Transmitting precoding matrix index information to the base station, wherein the precoding matrix index information is selected and / or selected from a first precoding matrix index indicating a selected first codeword (V _V ). Comprising a second precoding matrix index indicating a second codeword (V _H ). Selecting a third codeword (V _S ) suitable for the channel based on the channel information corresponding to the channel and the number of streams;
The method of claim 6, wherein the precoding matrix index information transmitted to the base station further comprises a third precoding matrix index indicating a selected third codeword (V _S ). An apparatus for generating a code book for wireless communication, wherein the code book includes a first code book and a second code book,
The first codebook (V _∀ ) has the following formula:
Wherein L is the number of codewords in the first codebook (V _∀ ), M is the number of horizontal antenna ports, N is the number of vertical antenna ports, Z _l represents the l columns in any existing codebook Z for wireless communication, the magnitude of Z is N rows and L columns, and modules,
The second codebook (V _H ) is _expressed by the following formula:
Wherein K indicates the number of codewords in the second codebook (V _H ), M indicates the number of horizontal antenna ports, and P indicates the number of columns of the matrix X. , B _k denote the k-th column of matrix B, where matrix B is:
m = 1, ..., M / 2, k = 1, ..., K
A device comprising a module. The codebook for wireless communication further comprises a third codebook (V _S ), the device comprising:
A third codebook (V _S ) can be expressed as:
Further comprising a module configured to determine according to
Q indicates the number of codewords in the third codebook (V _S ), P is the number of columns of the matrix X used in the second codebook, r indicates the number of streams,
9. The apparatus of claim 8, wherein denotes a vector having t elements, the sth element is 1, and the remaining elements are 0. An apparatus for generating a precoder for a 3D channel in a base station in wireless communication, characterized in that the codebook generated by the method according to claim 1 or 2 is used.
Based on the channel information of the 3D channel, a first codeword (V _V ) and a second codeword (V _H ) suitable for the 3D channel are selected from the first codebook and the second codebook, respectively. A module configured with:
And a module configured to generate a precoder (T) for the 3D channel based on a product of the first codeword (V _V ) and the second codeword (V _H ). A module configured to select a third codeword (V _S ) suitable for the 3D channel from the third codebook based on the channel information corresponding to the channel and the number of streams;
The module configured to generate a precoder for the 3D channel;
A precoder (T) for the 3D channel is generated based on a product of the first codeword (V _V ), the second codeword (V _H ), and the third codeword (V _S ). The apparatus of claim 10 configured. The channel information includes precoding matrix index information transmitted by a user equipment;
A module configured to receive precoding matrix index information from the user equipment, wherein the precoding matrix index information indicates a selected first codeword (V _V ). 12. An apparatus according to claim 10 or claim 11, further comprising a module comprising a second precoding matrix index indicating the index and the selected second codeword ( _VH ). The precoding matrix index information received from the user equipment further comprises a third precoding matrix index from the user equipment indicating a selected third codeword (V _S ). apparatus. An apparatus for facilitating precoder generation in a user equipment in wireless communication, characterized by using a codebook generated by the method according to claim 1 or 2.
Based on the channel information, a first codeword (V _V ) and / or a second codeword (V _H ) suitable for the channel are selected from the first codebook and / or the second codebook, respectively. A module configured with:
A module configured to transmit precoding matrix index information to a base station, wherein the precoding matrix index information indicates a first precoding matrix index indicating a selected first codeword (V _V ). And / or a module comprising a second precoding matrix index indicative of the selected second codeword (V _H ). A module configured to select a third codeword (V _S ) suitable for the channel based on the channel information and the number of streams corresponding to the channel;
The apparatus of claim 14, wherein the precoding matrix index information transmitted to the base station further comprises a third precoding matrix index indicating a selected third codeword (V _S ).